DHX9 maintains epithelial homeostasis by restraining R-loop-mediated genomic instability in intestinal stem cells.

Epithelial barrier dysfunction and crypt destruction are hallmarks of inflammatory bowel disease (IBD). Intestinal stem cells (ISCs) residing in the crypts play a crucial role in the continuous self-renewal and rapid recovery of intestinal epithelial cells (IECs). However, how ISCs are dysregulated in IBD remains poorly understood. Here, we observe reduced DHX9 protein levels in IBD patients, and mice with conditional DHX9 depletion in the intestinal epithelium (Dhx9ΔIEC) exhibit an increased susceptibility to experimental colitis. Notably, Dhx9ΔIEC mice display a significant reduction in the numbers of ISCs and Paneth cells. Further investigation using ISC-specific or Paneth cell-specific Dhx9-deficient mice demonstrates the involvement of ISC-expressed DHX9 in maintaining epithelial homeostasis. Mechanistically, DHX9 deficiency leads to abnormal R-loop accumulation, resulting in genomic instability and the cGAS-STING-mediated inflammatory response, which together impair ISC function and contribute to the pathogenesis of IBD. Collectively, our findings highlight R-loop-mediated genomic instability in ISCs as a risk factor in IBD.

Sporadic gastrinoma with refractory benign esophageal stricture: A case report.

BACKGROUND: Gastrinoma is characterized by an excessive release of gastrin, leading to hypersecretion of gastric acid, subsequently resulting in recurrent peptic ulcers, chronic diarrhea, and even esophageal strictures. This case report aims to improve awareness and facilitate early diagnosis and treatment of gastrinoma by presenting a rare case of gastrinoma with refractory benign esophageal stricture (RBES). Additionally, it highlights the persistent challenges that gastroenterologists encounter in managing RBES. CASE SUMMARY: This case demonstrates a patient with gastrinoma who developed RBES and complete esophageal obstruction despite management with maximal acid suppressive therapy, multiple endoscopic bougie dilations and endoscopic incisional therapy (EIT). CONCLUSION: It is essential to diagnose gastrinoma as early as possible, as inadequately controlled acid secretion over an extended period increases the risk of developing severe esophageal strictures. In patients with esophageal strictures causing complete luminal obstruction, blind reopening EIT presents challenges and carries a high risk of perforation.

Microbiome and its relevance to indigenous inflammatory bowel diseases in China.

BACKGROUND: Inflammatory Bowel Disease (IBD) is a chronic inflammatory disorder of the gastrointestinal tract with an unknown etiology. Although dysbiosis is implicated in its pathogenesis, deep sequencing and oral microbiota study in Chinese IBD patients is absent. AIM: To explore the role of oral / intestinal microbiota in patients with IBD and the potential associations therein. METHODS: Clinical data, fecal and saliva samples were harvested from 80 patients with IBD (Crohn's disease, CD, n = 69; Ulcerative colitis, UC, n = 11) and 24 normal controls. Microbiomics (16S rRNA sequencing and 16S rRNA full-length sequencing) were used to detect and analyze the difference between IBD patients and normal control. RESULTS: Compared with normal controls, a higher abundance of the intestinal Shigella spp. (Shigella flexneri and Shigella sonnei, which were positively relate to the severity of IBD), lower abundance of intestinal probiotics (Prevotella, Faecalibacterium and Roseburia), and higher abundance of oral Neisseria were present in IBD patients with microbiome. The higher inflammation-related markers, impaired hepatic and renal function, and dyslipidaemia were present in patients with IBD. A higher intake of red meat and increased abundance of Clostridium in the gut were found in CD patients, while the elevated abundance of Ruminococcus in the gut was showed in UC ones. The bacterial composition of saliva and fecal samples was completely different, yet there was some correlation in the distribution of dominant probiotics. CONCLUSION: Enteric dysbacteriosis and the infections of pathogenic bacteria (Shigella) may associate with the occurrence or development of IBD.

Evaluation of symptomatic small bowel stricture in Crohn's disease by double-balloon endoscopy.

PURPOSE: To assess the efficacy of double-balloon endoscopy (DBE) for the detection of small-bowel strictures in Crohn's disease (CD). METHODS: This tertiary-referral hospital cohort study was conducted between January 2018 and May 2022. CD patients with symptoms of small-bowel stricture were enrolled sequentially. All of the patients were subjected to both computed tomography enterography (CTE) and DBE, and their symptoms of stricture were assessed using the Crohn's Disease Obstructive Score (CDOS). The diagnostic yield of DBE was compared to that of CTE, and the relationship between the DBE findings and CDOS was investigated. The factors influencing the DBE diagnosis were examined using Cox regression analysis. RESULTS: This study included 165 CD patients. The CDOS scores were higher in 95 patients and lower in 70 patients. DBE detected 92.7% (153/165) and CTE detected 85.5% (141/165) of the strictures. The DBE diagnostic yields were 94.7% (90/95) in the high CDOS patients and 91.4% (64/70) in the low CDOS patients (P = 0.13). Patients with a history of abdominal surgery and abscess had a lower diagnosis rate in the multivariate analysis. CONCLUSION: DBE has been demonstrated to be an efficient diagnostic method for detecting small bowel strictures in CD patients. Additionally, there was no difference in the diagnostic yields between patients with low and high obstructive scores.

Interobserver Agreement among Cytopathologists in False-Negative Cases by Cytological Diagnosis with Endoscopic Ultrasound-Guided Fine Needle Aspiration in Solid Pancreatic Lesions.

INTRODUCTION: Early detection and accurate pathological assessment are critical to improving prognosis of pancreatic cancer. EUS has been widely used in diagnosing pancreatic lesions and can obtain histological diagnosis by endoscopic ultrasound-guided fine needle aspiration (EUS-FNA). However, comprehensive assessment of the interobserver agreement (IOA) among cytopathologists evaluating EUS-FNA specimens is still limited. Therefore, this study evaluated IOA among cytopathologists for EUS-FNA specimens of solid pancreatic lesions, especially in false-negative cases of cytological diagnosis and analyzed the factors that influence cytological diagnosis of EUS-FNA so as to improve the diagnostic efficiency of EUS-FNA. METHODS: We retrieved EUS-FNA samples of pancreatic solid lesions from 2017 to 2021 and collected their clinical/cytological data. Two cytopathologists independently reviewed these cases using a quoted, novel standardized cytology scoring tool. Ultimately, we calculated IOA among cytopathologists and performed a binary logistic regression analysis to evaluate factors influencing the cytological diagnosis of EUS-FNA. RESULTS: 161 patients were included, and 60 cases with a clinical diagnosis of pancreatic cancer but a cytological diagnosis of benign and atypical constituted the false-negative group. IOAs for cytological diagnosis of overall patients and the false-negative group were in perfect/moderate agreement with Kendall's W values of 0.896 and 0.462, respectively. The number of diagnostic cells in the scoring tool had the highest level of agreement (κ = 0.721) for overall patients. There was at best moderate agreement on other quantity and quality parameters for both all cases and false-negative group. Logistic regression analysis showed the number of diagnostic cells (OR = 6.110, p < 0.05) and amount of blood (OR = 0.320, p < 0.05) could influence cytological diagnosis. CONCLUSIONS: The false-negative rate of our study as high as 37.26% (60/161) is mainly related to strict standards of cytopathologists, and their ability to standardize pancreatic cytology is still improving. Suboptimal agreement among cytopathologists for cytological diagnosis and the number of diagnostic cells may be associated with the occurrence of false-negative diagnosis. Further regression analysis confirmed that the number of diagnostic cells and obscuring blood were important factors in cytological diagnosis. Therefore, refinement of cytological diagnostic criteria, standardization of specimen quality evaluation, and training of cytopathologists may improve the agreement of cytopathologists, thus improving the repeatability of cytological diagnosis and reducing the occurrence of false-negative events.

Efficacy and safety of esophageal submucosal tumors treated with internal traction method-assisted submucosal tunneling endoscopic resection: a single-center, single-blind, randomized controlled study.

BACKGROUND AND OBJECTIVES: Submucosal tunnel endoscopic resection (STER) is an effective technique for treating esophageal submucosal tumors, but the efficacy and safety of treating esophageal submucosal tumors with internal traction method-assisted STER have not been determined. The objectives of this study were to assess the feasibility, safety, and efficacy of internal traction method-assisted STER for the removal of esophageal submucosal tumors. PATIENTS AND METHODS: Eighty patients who underwent STER for esophageal submucosal tumors were included in the study. They were randomized and assigned to the two groups. The dual-knife method was used for STER. Forty patients underwent conventional STER (control group) and 40 underwent internal traction method-assisted STER in which self-made rubber band traction with clips was used (study group). In the study group, one end of the self-made rubber band was fixed on the surface of esophageal submucosal tumors with a clip, and the other end of the self-made rubber band was set on the anal side of the contralateral esophageal wall with a clip. RESULTS: STER was successful in all cases. Lesion features and demographics were similar between the two groups. In addition, broad exposure of the submucosal tissue was obtained by applying tension to the self-made rubber band traction with clips. The en bloc resection rate and complete resection rate were both 100% in the study group. However, the en bloc resection rate and complete resection rate were 85.0% and 100%, respectively, in the control group. Complications, such as perforation and pneumomediastinum, were significantly reduced in the study group, and there was a significant difference in the number of occurrences of bleeding, operation duration, fasting time, and patient length of stay between the study group and control group (P < 0.05). During the mean 13.7 month follow-up, there were no patients with esophageal fistula, recurrence, or distant metastasis in either group. CONCLUSIONS: This original study showed that esophageal submucosal tumors could be effectively and safely treated with internal traction method-assisted STER, and this technique might be superior to conventional STER due to its fewer complications, shorter operation duration, and shorter inpatient length of stay.

The Mechanosensitive Ion Channel PIEZO1 in Intestinal Epithelial Cells Mediates Inflammation through the NOD-Like Receptor 3 Pathway in Crohn's Disease.

BACKGROUND: Crohn's disease (CD) is an incurable chronic intestinal inflammatory disease with no recognized cause. It has been reported that the mechanosensitive ion channel PIEZO1 initiates proinflammatory responses. However, little is known about the role of PIEZO1 in CD. METHODS: Ileum biopsies were obtained from 30 patients with CD and 15 healthy volunteers. Clinical data were collected to determine the relationship between CD and PIEZO1. First, HT29 cells were incubated with Yoda1 and GsMTx4 (Grammostola spatulata mechanotoxin 4) to activate and inhibit PIEZO1, respectively. Second, PIEZO1 knockdown was performed using small interfering RNA. Third, calcium imaging, flow cytometry, and immunofluorescence were used to detect intracellular calcium and mitochondrial function. Last, real-time quantitative polymerase chain reaction, immunoblotting, and enzyme-linked immunosorbent assay were used to quantify PIEZO1, proinflammatory cytokines, and NLRP3 (NOD-like receptor 3)-related compounds. RESULTS: PIEZO1 was highly expressed in the ileum of patients with CD and correlated positively with the Crohn's Disease Activity Index, platelet count, and hematocrit and fecal calprotectin levels. In HT29 cells, Yoda1 triggered calcium influx, which was inhibited by GsMTx4 treatment and small interfering RNA-mediated PIEZO1 knockdown. Increased calcium concentrations resulted in increased reactive oxygen species accumulation and decreased mitochondrial membrane potential, whereas decreased calcium concentrations caused by GsMTx4 and PIEZO1 knockdown had the opposite effect. Mechanistically, molecules in the NLRP3 pathway were activated in patients with CD and HT29 cells were stimulated by lipopolysaccharide; these effects were reversed by the knockdown of PIEZO1. Finally, PIEZO1 and NLRP3 knockdown decreased proinflammatory cytokine levels in HT29 cells. CONCLUSIONS: PIEZO1 in intestinal epithelial cells caused calcium influx, which resulted in mitochondrial dysfunction and activated the NLRP3 inflammasome, mediating intestinal inflammation.

PIEZO1 was highly expressed in patients with active Crohn's disease. Its expression was significantly increased in the ileum and was associated with intestinal inflammation. In intestinal epithelial cells, PIEZO1 triggered calcium influx, resulting in mitochondrial dysfunction, and activated the NLRP3 inflammasome, thereby mediating intestinal inflammation.

Expression of 5-hydroxytryptamine 7 receptor in intestinal mucosa correlates with the degree of intestinal inflammation in Crohn's disease.

BACKGROUND: Crohn's disease (CD), an inflammatory bowel disease (IBD), is a complex and heterogeneous disease characterized by nonspecific transmural inflammation of the gastrointestinal tract. CD has a variety of potential causes with no effective treatment available yet. Current clinical laboratory findings from patients do not provide direct indication of the status of mucosal inflammation in the intestine. Recently, it has been found that intestinal inflammation is generally associated with increased levels of 5-hydroxytryptamine (5-HT), which acts as an important gastrointestinal signaling molecule in intestinal homeostasis by stimulating specific receptors. Most previous researches were carried out in vitro or with animal models, and there was a lack of authentic clinical research. In this study, clinical specimens from patients with Crohn's disease were used to investigate the expression of 5-hydroxytryptamine 7 receptor (5-HT7R) in the induction and development of chronic non-specific inflammatory bowel disease. METHODS: Patients with CD admitted to the Department of Gastroenterology in the First Affiliated Hospital of Anhui Medical University between June 2014 and January 2018 were recruited, among which 28 were in active disease and 32 were in remission. In addition, 20 patients who had no obvious abnormality by colonoscopy in the hospital during the same time period were recruited into the control group. Data of clinical disease activity (CDAI), CD endoscopic score (SES-CD) and magnetic resonance score (MaRIA) were collected from those two groups of patients. The expression and distribution of 5-HT7R were investigated and their correlations with clinical CDAI, MaRIA, and endoscopic SES-CD scores were analyzed. RESULTS: Our study demonstrated that 5-HT7R is expressed in intestinal neurons and CD11C-positive cells in human colon. In CD11c/CD86 double-positive cells in the bowel, 5-HT7R expression was significantly increased in the inflammatory area in the bowel of CD patients, and it was closely related to disease severity, MaRIA, and SES-CD scores. CONCLUSION: The expression of 5-HT7R was significantly correlated with the degree of gut inflammation in CD patients and could be a potential biomarker for disease activity and the therapeutic efficacy in patients with Crohn's Disease.

LncRNA PSR Regulates Vascular Remodeling Through Encoding a Novel Protein Arteridin.

RATIONALE: Vascular smooth muscle cells (VSMCs) phenotype switch from contractile to proliferative phenotype is a pathological hallmark in various cardiovascular diseases. Recently, a subset of long noncoding RNAs was identified to produce functional polypeptides. However, the functional impact and regulatory mechanisms of long noncoding RNAs in VSMCs phenotype switching remain to be fully elucidated. OBJECTIVES: To illustrate the biological function and mechanism of a VSMC-enriched long noncoding RNA and its encoded peptide in VSMC phenotype switching and vascular remodeling. RESULTS: We identified a VSMC-enriched transcript encoded by a previously uncharacterized gene, which we called phenotype switching regulator (PSR), which was markedly upregulated during vascular remodeling. Although PSR was annotated as a long noncoding RNA, we demonstrated that the lncPSR (PSR transcript) also encoded a protein, which we named arteridin. In VSMCs, both arteridin and lncPSR were necessary and sufficient to induce phenotype switching. Mechanistically, arteridin and lncPSR regulate downstream genes by directly interacting with a transcription factor YBX1 (Y-box binding protein 1) and modulating its nuclear translocation and chromatin targeting. Intriguingly, the PSR transcription was also robustly induced by arteridin. More importantly, the loss of PSR gene or arteridin protein significantly attenuated the vascular remodeling induced by carotid arterial injury. In addition, VSMC-specific inhibition of lncPSR using adeno-associated virus attenuated Ang II (angiotensin II)-induced hypertensive vascular remodeling. CONCLUSIONS: PSR is a VSMC-enriched gene, and its transcript IncPSR and encoded protein (arteridin) coordinately regulate transcriptional reprogramming through a shared interacting partner, YBX1. This is a previously uncharacterized regulatory circuit in VSMC phenotype switching during vascular remodeling, with lncPSR/arteridin as potential therapeutic targets for the treatment of VSMC phenotype switching-related vascular remodeling.

Fecal calprotectin predicts endoscopic activity and mucosal healing of small bowel Crohn's disease evaluated by double-balloon endoscopy.

PURPOSE: Fecal calprotectin (FC) levels can reflect the level of intestinal inflammation. Crohn's disease (CD), which affects the small bowel, has not been linked to FC levels. We determined if FC levels and endoscopic activity were related by performing double-balloon endoscopy (DBE). METHODS: Herein, patients with small bowel CD diagnosed by DBE between January 2020 and January 2022 were prospectively observed. Feces and blood samples of patients were collected before performing DBE and checked for the levels of FC and serological biomarkers. The endoscopic activity and mucosal healing (MH) were evaluated using the partial simple endoscopic score (pSES-CD). RESULTS: In all 254 CD patients, FC levels were correlated with pSES-CD (r = 0.775, P < 0.001). Even in patients with isolated small bowel CD, FC levels were strongly correlated with pSES-CD (r = 0.753, P < 0.001). In all patients, FC as an endoscopic remission indicator was found to have an area under the curve (AUC) of 0.872, with a cut-off value of 156.09 µg/g. In patients with isolated small bowel CD, FC yielded a high AUC of 0.865 for predicting endoscopic remission, with a cut-off value of 211.48 µg/g, sensitivity of 73.95%, and specificity of 91.30%. FC was optimally cut-off at 76.99 µg/g to predict MH in accordance with the AUC of 0.877. CONCLUSIONS: Using DBE findings, FC was found to be significantly correlated with pSES-CD. Even in isolated small bowel CD, FC may be a more reliable marker of accurately predicting endoscopic remission and MH.

Molecular mechanism of the TGF­ß/Smad7 signaling pathway in ulcerative colitis.

Aberrant TGF­ß/Smad7 signaling has been reported to be an important mechanism underlying the pathogenesis of ulcerative colitis. Therefore, the present study aimed to investigate the effects of a number of potential anti­colitis agents on intestinal epithelial permeability and the TGF­ß/Smad7 signaling pathway in an experimental model of colitis. A mouse model of colitis was first established before anti­TNF­α and 5­aminosalicyclic acid (5­ASA) were administered intraperitoneally and orally, respectively. Myeloperoxidase (MPO) activity, histological index (HI) of the colon and the disease activity index (DAI) scores were then detected in each mouse. Transmission electron microscopy (TEM), immunohistochemical and functional tests, including Evans blue (EB) and FITC­dextran (FD­4) staining, were used to evaluate intestinal mucosal permeability. The expression of epithelial phenotype markers E­cadherin, occludin, zona occludens (ZO­1), TGF­ß and Smad7 were measured. In addition, epithelial myosin light chain kinase (MLCK) expression and activity were measured. Anti­TNF­α and 5­ASA treatments was both found to effectively reduce the DAI score and HI, whilst decreasing colonic MPO activity, plasma levels of FD­4 and EB permeation of the intestine. Furthermore, anti­TNF­α and 5­ASA treatments decreased MLCK expression and activity, reduced the expression of Smad7 in the small intestine epithelium, but increased the expression of TGF­ß. In mice with colitis, TEM revealed partial epithelial injury in the ileum, where the number of intercellular tight junctions and the expression levels of E­cadherin, ZO­1 and occludin were decreased, all of which were alleviated by anti­TNF­α and 5­ASA treatment. In conclusion, anti­TNF­α and 5­ASA both exerted protective effects on intestinal epithelial permeability in an experimental mouse model of colitis. The underlying mechanism may be mediated at least in part by the increase in TGF­ß expression and/or the reduction in Smad7 expression, which can inhibit epithelial MLCK activity and in turn reduce mucosal permeability during the pathogenesis of ulcerative colitis.

Detection of a novel antigen for Crohn's disease.

BACKGROUND AND AIMS: Accurate serological assays are desirable for the diagnosis of inflammatory bowel disease (IBD). We identify an antigen-like substance called Crohn's disease (CD) antibody binding polypeptide (CABP). As a serological marker, anti-CABP may contribute to the diagnosis of IBD. The present study aims to evaluate the clinical role of anti-CABP as a serological antibody for IBD. METHODS: Using enzyme-linked immunosorbent assay (ELISA), serum anti-CABP, anti-Saccharomyces cerevisiae antibody (ASCA) and perinuclear anti-neutrophil cytoplasmic antibody (pANCA), titers were tested in 168 CD patients, 123 ulcerative colitis (UC) patients and 170 controls. The correlation between serum antibody and clinical characteristics was investigated. The diagnostic potential of the anti-CABP was evaluated by receiver operating characteristic (ROC) analysis. RESULTS: The titers of anti-CABP (IgA or IgG) and ASCA IgG of CD patients were significantly higher than non-CD group (all p < .01). In the differential diagnosis of CD and non-CD, anti-CABP IgA revealed an area under the curve (AUC) of 0.706 and anti-CABP IgG demonstrated an AUC of 0.788. As an individual antibody, anti-CABP could effectively distinguish CD from non-CD (AUC 0.816), and the diagnostic efficacy was better than that of ASCA (AUC 0.680). The combined use of anti-CABP, ASCA and pANCA significantly improved the diagnostic value (AUC 0.857). Anti-CABP positive rates were associated with perianal lesions and disease location in CD patients (both p < .05). CONCLUSIONS: Our results suggested that anti-CABP could be used as a serological marker to assist the diagnosis of CD. CLINICAL TRIAL REGISTRATION: This trial is registered with clinical trial registration unique identifier ChiCTR2000037094.

Chromoendoscopy with targeted biopsies is superior to white-light endoscopy for the long-term follow-up detection of dysplasia in ulcerative colitis patients: a multicenter randomized-controlled trial.

BACKGROUND: Data from single-center experience or small sample-sized studies have shown that chromoendoscopy (CE) might be superior to white-light endoscopy (WLE) for dysplasia surveillance in ulcerative colitis (UC) patients. We performed a prospective randomized trial with a long-term follow-up to compare the detection rate of dysplasia among WLE with targeted biopsies (WLT), WLE with random biopsies (WLR), and dye-based CE with targeted biopsies (CET) in UC patients. METHODS: Patients with long-standing UC were enrolled from 11 medical centers from March 2012 to December 2013 and randomized into three arms (WLT, WLR, and CET). Only high-definition endoscopy was used in all three groups. The patients were followed up by annual endoscopy with biopsies through December 2017. RESULTS: With a median follow-up time of 55 months, a total of 122 patients with 447 colonoscopies were finally analysed in the per-protocol set: WLT (n = 43), WLR (n = 40), and CET (n = 39). A total of 34 dysplastic lesions were found in 29 colonoscopies of 21 patients. WLR and CET could identify more colonoscopies that diagnosed dysplasia than WLT (8.1% and 9.7% vs 1.9%; P = 0.014 and 0.004, respectively). WLR obtained more biopsied samples than WLT and CET (16.4 ± 5.1 vs 4.3 ± 1.4 and 4.3 ± 1.4; both P < 0.001). During the second half of the follow-up (37 - 69 months), CET could identify more colonoscopies that diagnosed dysplasia than WLT (13.3% vs 1.6%, P = 0.015) and showed a trend for increasing the detection rate compared with WLR (13.3% vs 4.9%, P = 0.107). CONCLUSIONS: For a better outcome of cancer/dysplasia surveillance in patients with long-standing UC, CET appeared to be more effective than WLT and less tedious than WLR. CET was found to be particularly useful when a long-term (>3 years) follow-up was conducted for dysplasia surveillance. The trial was registered on www.chictr.org.cn (ChiCTR1900023689).

Retracted: AIB1 induces epithelial-mesenchymal transition in gastric cancer via the PI3K/AKT signaling.

Amplified in breast cancer 1 (AIB1) is overexpression in various cancers and promotes tumor cell proliferation, survival, and invasiveness. However, the role of AIB1 in the regulation of gastric cancer (GC) cell epithelial-mesenchymal transition (EMT) is still largely unclear. In the present study, immunohistochemistry showed that AIB1 was upregulated in our cohort of patients with GC and correlated with poor survival. Knockdown of AIB1 reduced the invasive ability of GC cells, downregulated the expression of epithelial cell marker E-cadherin, and upregulated mesenchymal cell marker vimentin. AIB1 overexpression elicited the opposite effect. PI-103, the inhibitor of the PI3K/AKT signaling, partially reversed AIB1 overexpression mediated a decrease in E-cadherin and an increase in vimentin. The present data demonstrated that AIB1 augmented the EMT via activation of PI3K/AKT signaling. In conclusion, our results suggested a novel role of AIB1 in GC invasion and EMT and raised the possibility of using this molecule as an indicator for GC treatment.

PAP-1 ameliorates DSS-induced colitis with involvement of NLRP3 inflammasome pathway.

BACKGROUND: Macrophages are a primary type of innate immune cells activated in colitis. Kv1.3 channel is one of the major potassium channels in macrophages. NLRP3 inflammasome is a downstream molecule of Kv1.3 channel. PAP-1, a specific Kv1.3 channel blocker, has been shown to have immune-regulatory effects. OBJECTIVE: To investigate the effect of PAP-1 on intestinal inflammation in DSS-induced colitis and explore its possible mechanism. METHODS: C57BL/6 mice were divided into four groups: normal control group, normal+PAP-1 injection group, DSS model group, DSS model+PAP-1 injection group. Experimental colitis was induced by 5% DSS treatment; mice were injected intraperitoneally with PAP-1 from the first day for 7 consecutive days; then all mice were sacrificed, followed by isolation of colon tissue, peritoneal macrophages and spleen macrophages. The anti-inflammatory effects of PAP-1 and the expression levels of Kv1.3, iNOS, pro-IL-1ß, IL-1ß and NLRP3 inflammasome were measured. RESULTS: PAP-1 reduced DSS-induced colonic pathological damage, DAI score, MPO activity and levels of IL-1, IL-6, TNF-a, IL-18. Compared with the DSS model group, the expression of Kv1.3, iNOS, NLRP3, ASC, caspase-1p20, pro-IL-1ß and IL-1ß in colon were decreased in the DSS-induced colitis mice with PAP-1 injection. PAP-1 also reduced the expression of Kv1.3, iNOS, NLRP3, caspase-1p20 and IL-1ß on macrophages in colitis mice. CONCLUSION: PAP-1 had protective effects on DSS-induced colitis, which might be ascribed to the regulation of NLRP3 inflammasome pathway. Therefore, we found that PAP-1 was useful as a therapeutic agent in IBD and suggested a potential important role of PAP-1 in NLRP3 inflammasome-associated diseases.

Risk factors for colorectal neoplasia in patients with underlying inflammatory bowel disease: a multicenter study.

BACKGROUND: This study sought to evaluate the risk factors for the development of colitis-associated neoplasia (CAN) in Chinese patients with inflammatory bowel disease (IBD). METHODS: IBD patients who developed CAN between 1999 and 2016 were identified from eight medical centers. In addition to initial pathology evaluation, a CAN diagnosis was confirmed by two expert pathologists. Patients with CAN (n = 29) were compared with non-CAN controls (n = 87). Matching was performed for gender and IBD type with a ratio of three controls to one subject. RESULTS: Of the 29 patients with CAN, 8 (27.6%) had colorectal cancer (CRC), 20 (69.0%) had a final diagnosis of low-grade dysplasia and 1 (3.4%) had high-grade dysplasia. Multivariate analysis revealed that an older age at the time of IBD diagnosis and a longer IBD duration were independent risk factors for the development of CAN, with odds ratios of 1.09 [95% confidence interval (CI): 1.04-1.14, P < 0.001] and 1.14 (95% CI: 1.03-1.27, P = 0.013), respectively. Comparison between IBD patients with CRC and those with dysplasia indicated that the former were older at the time of IBD diagnosis (P = 0.012) and had longer IBD durations (P = 0.019). CONCLUSIONS: Older age at the time of IBD diagnosis and longer IBD duration were found to be associated with the development of CAN in IBD patients.

Measurement of red blood cell 6-thioguanine nucleotide is beneficial in azathioprine maintenance therapy of Chinese Crohn's disease patients.

OBJECTIVE: It remains controversial whether 6-thioguanine nucleotide (6-TGN)-based dose adjusting can be beneficial in azathioprine (AZA) therapy. This study is designed to assess the role of 6-TGN concentrations in maintaining clinical remission in Chinese patients with Crohn's disease (CD). MATERIAL AND METHOD: We performed a prospective observational study and collected data of CD patients in the First Affiliated Hospital of Anhui Medical University from June 2013 to April 2014. Demographic material, CD activity index, 6-TGN concentration, and laboratory tests were recorded at baseline and at each visit. In addition, 6-TGN was measured when drug adverse effects occurred. All patients achieved maintenance stage were administered a stable AZA dose at least 3 months before enrollment and were followed up at least 12 months. Thiopurine S-methyltransferase (TPMT) genotype was measured before AZA treatment. RESULTS: Sixty-nine patients receiving maintenance therapy were analyzed. A positive correlation was found between 6-TGN levels and AZA dose (r = 0.258, p = 0.032). The mean 6-TGN concentration was 302.06 ± 115.84 in the remission group vs. 264.94 ± 164.53 pmol/8 × 10(8) RBC in those with active disease (t = 0.847, p = 0.40), and 197.74 ± 66.54 pmol/8 × 10(8) RBC in patients who relapsed vs. 310.26 ± 122.38 pmol/8 × 10(8) RBC for those in sustained remission (t= -2.541, p = 0.013). In the leukopenia group, the 6-TGN concentration was 469.11 ± 115.53 pmol/8 × 10(8) RBC vs. 257.31 ± 83.74 pmol/8 × 10(8) RBC in the non-leukopenia group (t = 7.622, p < 0.001). There was a significant negative correlation between leukocyte count and 6-TGN concentration (r= -0.326, p = 0.006). CONCLUSIONS: 6-TGN measurement is a helpful method of preventing disease relapse and avoiding leukopenia in individual azathioprine maintenance therapy.

Association of MYO9B gene polymorphisms with inflammatory bowel disease in Chinese Han population.

AIM: To explore the association of MYO9B gene polymorphisms with clinical phenotypes and intestinal permeability of individuals with inflammatory bowel disease (IBD) in China. METHODS: A total of 442 IBD patients and 402 healthy volunteers were genotyped for two single nucleotides (rs962917 and rs1545620) using the ligase detection reaction and polymerase chain reaction. Allelic and genotype frequency analyses were performed for the two groups. Intestinal permeability was evaluated using lactulose (L) and mannitol (M) excretion. The association of MYO9B gene polymorphisms with intestinal permeability between the normal and high intestinal permeability groups was analyzed. RESULTS: Overall, there was no significant difference in the genotypic and allelic frequencies of MYO9B between IBD patients and controls. Although no association was found with ulcerative colitis in the comparison between the subgroups, the frequencies of rs962917 and rs1545620 were different in the Crohn's disease (CD) subgroup with ileocolitis (CC vs CT and TT, P = 0.014; and AA vs AC and CC, P = 0.022, respectively). rs1545620 variants appear to be the genetic susceptibility factor for perianal disease in CD patients (AA vs AC CC, P = 0.029). In addition, the L/M ratio was significantly higher in IBD patients than in controls (0.065 ± 0.013 vs 0.020 ± 0.002, P = 0.02), but no association was found between the MYO9B gene and the L/M ratio in IBD patients. CONCLUSION: MYO9B gene polymorphisms may influence the sub-phenotypic expression of CD in China. No association between these MYO9B polymorphisms and intestinal permeability in IBD patients was found.